Image processing apparatus and image processing method

ABSTRACT

An image processing apparatus for achieving the exchange of pieces of image data between a plurality of image processing apparatuses includes: a feature value extraction unit for extracting a feature value included in image data; a feature value transfer unit for transferring to another image processing apparatus a feature value extracted from image data to be exchanged; a feature value reception unit for receiving a feature value transferred from the other image processing apparatus; a first determination unit for determining whether the received feature value matches a feature value included in image data of a captured image; an image data transfer unit for transferring the image data of the captured image to the other image processing apparatus when there is a match between the feature values; and an image data reception unit for receiving image data of a captured image transferred from the other image processing apparatus.

CROSS REFERENCES TO RELATED APPLICATIONS

The present invention contains subject matter related to Japanese PatentApplication JP 2007-260300 filed in the Japanese Patent Office on Oct.3, 2007, the entire contents of which are incorporated herein byreference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an image processing apparatus and animage processing method.

2. Description of the Related Art

In recent years, a technique for exchanging pieces of image data ofimages captured by a plurality of image pickup apparatuses such asdigital cameras or video cameras among these image pickup apparatuseshas been developed. In such an exchange of pieces of image data, imagedata is transferred from one image pickup apparatus to another imagepickup apparatus via a wire/wireless communication link with or withouta server.

Japanese Unexamined Patent Application Publication No. 2006-59331discloses an image data exchange method. In this method, each camerauser registers identification information in a server in advance. Whenthe server receives image data and identification information which havebeen uploaded thereto, it distributes the image data to a usercorresponding to the identification information. Accordingly, thismethod is used in a case in which a plurality of cameras included in animage capturing group register common identification information so asto share image data.

Japanese Unexamined Patent Application Publication No. 2006-254098discloses an image data exchange method. In this method, a plurality ofcamera users set common identification information in advance. The userscause cameras owned by the users to automatically store obtained imagedata along with the identification information. Upon receiving a requestincluding the identification information from one of cameras sharing theidentification information, another camera reads out stored image dataassociated with the identification information, and transmits the imagedata to the camera. At that time, the connection between these camerasis established by the users of the cameras.

SUMMARY OF THE INVENTION

In some cases, a user may want to obtain image data of an imageincluding a specific subject, for example, a photographer, using animage data exchange method.

In the method disclosed in Japanese Unexamined Patent ApplicationPublication No. 2006-59331, however, the checking of subject image dataincluded in image data is not performed. One of cameras included in animage capturing group transmits (uploads) pieces of image data of allimages captured by the camera to a server. Another camera receives thepieces of image data of all the images from the server and stores them.In order to obtain image data including data of a specific subject, theuser of the camera has to check all the pieces of image data receivedone by one so as to determine whether the data of the specific subjectis included, and delete unnecessary pieces of image data.

In the method disclosed in Japanese Unexamined Patent ApplicationPublication No. 2006-254098, it is necessary for each user to setidentification information. Accordingly, in order to obtain image dataincluding data of a specific subject, each user has to determine whetherimage data is to be exchanged each time image capturing is performed andset identification information in accordance with the determinationresult. Thus, each user has to perform a complicated operation. If thenumber of pieces of setting identification information is limited, it isdifficult to specify image data including data of a desired subject. Inthis method, before transferring image data to be exchanged, a user hasto perform a connection establishment operation for specifying a camerato which the image data is to be transferred. Accordingly, if image datais transferred to an indefinite number of cameras, a user has to performa complicated connection establishment operation. Furthermore, sinceimage data stored in advance is transferred, it is difficult to transferimage data at the time of image capturing. A user has to perform atransfer operation separately from image capturing.

Thus, in the case of image data exchange methods in the related art,user operations including mutual authentication for establishing theconnection between a server and a camera or between cameras areperformed. Furthermore, all or parts of pieces of stored image data aretransferred without performing checking of subject image data includedin the pieces of image data. Accordingly, a user checks a plurality ofpieces of transferred image data one by one so as to determine whetherdesired subject image data is included and then deletes unnecessarypieces of image data. Alternatively, a user determines whether obtainedimage data is desired image data each time image capturing is performed,and then performs a connection establishment operation.

The checking of image data, the connection establishment operation, orthe deletion of image data is an operational burden imposed on a user.This may reduce the efficiency of image capturing. Furthermore, byperforming inefficient user's operations such as the connectionestablishment operation performed each time image data is transferredand the transfer and deletion of unnecessary image data, electric powerfor the operation of a camera is wasted. As a result, it is difficult toobtain sufficient electric power at the time of image capturing.Accordingly, the efficiency of image capturing may be further reduced.

It is desirable to provide an image processing apparatus and an imageprocessing method capable of achieving the efficient exchange of piecesof image data between a plurality of image processing apparatuses.

According to a first embodiment of the present invention, there isprovided an image processing apparatus for achieving the exchange ofpieces of image data between a plurality of image processingapparatuses. The image processing apparatus includes: a feature valueextraction unit configured to extract a feature value included in imagedata; a feature value transfer unit configured to transfer to anotherimage processing apparatus a feature value extracted from image data tobe exchanged; a feature value reception unit configured to receive afeature value transferred from the other image processing apparatus; afirst determination unit configured to determine whether the receivedfeature value matches a feature value included in image data of acaptured image; an image data transfer unit configured to transfer theimage data of the captured image to the other image processing apparatuswhen there is a match between the feature values; and an image datareception unit configured to receive image data of a captured imagetransferred from the other image processing apparatus.

In the image processing apparatus having the above-describedconfiguration, a feature value included in image data is extracted, anda feature value extracted from image data to be exchanged is transferredto another image processing apparatus. A feature value transferred fromthe other image processing apparatus is received, a feature valueincluded in image data is extracted, and it is determined whether thereceived feature value matches the feature value included in the imagedata. If there is a match between the feature values, the image data istransferred to the other image processing apparatus. Furthermore, imagedata transferred from the other image processing apparatus is received.Thus, on the basis of the feature value included the image data to beexchanged, corresponding image data is transferred to/from the otherimage processing apparatus. Accordingly, a plurality of image processingapparatuses can efficiently exchange pieces of image data to beexchanged.

The feature value transfer unit may transfer identification informationallowing identification of the image processing apparatus from which thefeature value extracted from image data to be exchanged is to betransferred along with the extracted feature value. The feature valuereception unit may receive identification information of the other imageprocessing apparatus from which the feature value has been transferredalong with the transferred feature value. When the first determinationunit determines that there is a match between the feature values, theimage data transfer unit may transfer to the other image processingapparatus the identification information of the other image processingapparatus from which the feature value has been transferred and thenbeen received along with the image data of the captured image. The imagedata reception unit may receive from the other image processingapparatus the identification of the image processing apparatus fromwhich the feature value included in the image data of the captured imagehas been transferred along with the image data of the captured image.The image processing apparatus may further include a seconddetermination unit configured to determine whether the identificationinformation received from the other image processing apparatus matchesidentification information of the image processing apparatus that hasreceived the identification information from the other image processingapparatus. Thus, the feature value extracted from the image data to beexchanged and the identification information allowing identification ofthe image processing apparatus from which the extracted feature value isto be transferred are transferred to the other image processingapparatus. The feature value and the identification information of theother image processing apparatus from which the feature value has beentransferred are received from the other image processing apparatus. Itis determined whether the received identification information matchesidentification information of the image processing apparatus that hasreceived the identification information from the other image processingapparatus. As a result, corresponding image data and the identificationinformation of an image processing apparatus that wants to obtain theimage data are transferred to/from the other image processing apparatus.Accordingly, a plurality of image processing apparatuses can efficientlyexchange pieces of image data to be exchanged on the basis of thedetermination result of identification information.

The image processing apparatus may further include an image data storageunit configured to store the received image data of the captured image.As a result, since the received image data is stored, image data to beexchanged can be easily stored.

The image processing apparatus may further include an image data storageunit configured to store the received image data of the captured imagewhen the second determination unit determines that there is a matchbetween the pieces of identification information. Thus, if there is amatch between the pieces of identification information, the receivedimage data is stored. Accordingly, image data to be exchanged can beeasily stored on the basis of the determination result of identificationinformation.

The image processing apparatus may further include a feature valuestorage unit configured to store a plurality of feature values receivedfrom the other image processing apparatus. The first determination unitmay determine whether the feature value included in the image data ofthe captured image matches the stored feature values. The image datatransfer unit may transfer to the other image processing apparatus theimage data of the captured image when there is a match among the featurevalues. Thus, a plurality of feature values received from the otherimage processing apparatus are stored. It is determined whether thestored feature values match the feature value included in the imagedata. If there is a match among these feature values, the image data istransferred to the other image processing apparatus. As a result, sincecorresponding image data is transferred to/from the other imageprocessing apparatus on the basis of the stored feature values, aplurality of image processing apparatuses can efficiently exchangepieces of image data to be exchanged.

The image processing apparatus may further include a feature valuestorage unit configured to store a plurality of feature values receivedfrom the other image processing apparatus and identification informationof the other image processing apparatus from which the feature valueshave been transferred. The first determination unit may determinewhether the feature value included in the image data of the capturedimage matches the stored feature values. When there is a match among thefeature values, the image data transfer unit may transfer to the otherimage processing apparatus the identification information of the otherimage processing apparatus from which the feature values have beentransferred along with the image data of the captured image. Thus, aplurality of feature values received from the other image processingapparatus and the identification information of the other imageprocessing apparatus from which the feature values have been transferredare stored. It is determined whether the stored feature values match thefeature value included in the image data. If there is a match amongthese feature values, the image data and the identification informationof the other image processing apparatus from which the feature valueshave been transferred are transferred to the other image processingapparatus. As a result, since corresponding image data and theidentification information of an image processing apparatus that wantsto obtain the image data are transferred to/from the other imageprocessing apparatus, a plurality of image processing apparatuses canefficiently exchange pieces of image data to be exchanged on the basisof the determination result of the stored feature values.

The feature value extraction unit may extract a feature value of asubject face image included in image data. The first determination unitmay determine whether the extracted feature value of the subject faceimage matches a feature value of a subject face image received from theother image processing apparatus. Thus, the feature value of a subjectface image is extracted, and it is determined whether the extractedfeature value of the subject face image matches a feature value of asubject face image received from the other image processing apparatus.As a result, a plurality of image processing apparatuses can efficientlyexchange corresponding pieces of image data on the basis of the featurevalue of a subject face image.

According to a second embodiment of the present invention, there isprovided an image processing method of achieving the exchange of piecesof image data between a plurality of image processing apparatuses. Theimage processing method includes the steps of: receiving a feature valueincluded image data to be exchanged from another image processingapparatus; extracting a feature value included in image data of acaptured image; determining whether the extracted feature value matchesthe received feature value; and transferring the image data of thecaptured image to the other image processing apparatus when there is amatch between the feature values.

In the above-described image processing method, first, an imageprocessing apparatus receives a feature value included in image data tobe exchanged from another image processing apparatus. The imageprocessing apparatus extracts a feature value included in image data,determines whether the extracted feature value matches the receivedfeature value, and transfers the image data to the other imageprocessing apparatus when there is a match between the feature values.As a result, since corresponding image data is transferred to anotherimage processing apparatus on the basis of a feature value included inimage data to be exchanged, the other image processing apparatus canefficiently obtain desired image data.

In the receiving step, identification information allowingidentification of the other image processing apparatus from which thefeature value included in image data to be exchanged has beentransferred may be received along with the feature value. In thetransferring step, when it is determined in the determining step thatthere is a match between the feature values, the identificationinformation of the other image processing apparatus from which thefeature value has been transferred and then been received may betransferred to the other image processing apparatus along with the imagedata of the captured image. Thus, first, the image processing apparatusreceives a feature value and identification information allowingidentification of the other image processing apparatus from which thefeature value has been transferred. If it is determined that there is amatch between the received feature value and the extracted featurevalue, the image processing apparatus transfers to the other imageprocessing apparatus image data and the identification information ofthe other image processing apparatus from which the feature value hasbeen transferred and then been received. As a result, sincecorresponding image data and the identification information of an imageprocessing apparatus that wants to obtain the image data are transferredto the other image processing apparatus, the other image processingapparatus can efficiently obtain the desired image data by determiningwhether the transferred image data is image data to be exchanged on thebasis of the transferred identification information.

According to an embodiment of the present invention, there can beprovided an image processing apparatus and an image processing methodcapable of achieving the exchange of pieces of image data between aplurality of image processing apparatuses.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating an exemplary configuration of adigital camera having an image data exchange function;

FIG. 2 is a block diagram illustrating a main functional configurationof a camera according to a first embodiment;

FIG. 3 is a schematic diagram describing an image data exchange method(a feature value extraction and transfer process) according to the firstembodiment;

FIG. 4 is a schematic diagram describing an image data exchange method(a feature value comparison and image transfer process) according to thefirst embodiment;

FIG. 5 is a flowchart illustrating an image data exchange method (afeature value extraction and transfer process) according to the firstembodiment;

FIG. 6 is a flowchart illustrating an image data exchange method (afeature value comparison and image transfer process) according to thefirst embodiment;

FIG. 7 is a schematic diagram describing a feature value extraction andtransfer process performed when a plurality of feature values arespecified;

FIG. 8 is a block diagram illustrating a main functional configurationof a camera according to a second embodiment; and

FIG. 9 is a schematic diagram describing a feature value extraction andtransfer process performed in an image data exchange method according tothe second embodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Preferred embodiments of the present invention will be described indetail below with reference to the accompanying drawings. In thespecification and the drawings, like reference numerals are used forlike components and portions so as to avoid repeated explanation.

First Embodiment

An image data exchange method according to the first embodiment of thepresent invention will be described below.

FIG. 1 is a block diagram illustrating an exemplary configuration of adigital camera having an image data exchange function.

In a camera 100 illustrated in FIG. 1, light from a subject (notillustrated) is directed through a lens unit 12 having a lens and adiaphragm mechanism to a CCD 31 for photoelectric conversion and is theninput into a CDS (Correlated Double Sampling) circuit 32 as a videosignal.

The CDS circuit 32 performs correlated double sampling upon the inputsignal to remove noise and inputs the processed signal into an AGCcircuit 33. The AGC circuit 33 adjusts the gain of the input signal andinputs the processed signal into an A/D converter 34. The A/D converter34 converts the input signal (which is an analog signal) into a digitalsignal, and inputs the digital signal into a DSP 35.

The DSP 35 includes an image adjustment processor 41, an imagecompression/decompression processor 42, and an SDRAM controller 43. TheDSP 35 causes the image adjustment processor 41 to generate controlsignals used for automatic focusing, automatic exposure, automatic whitebalance, etc. on the basis of the input signal, and supplies thesecontrol signals to a CPU 51 via a bus 50. The DSP 35 causes the imagecompression/decompression processor 42 to compress input image datausing a predetermined compression/decompression method while causing theSDRAM controller 43 to control an SDRAM 36 so as to generate compressedimage data. Furthermore, the DSP 35 causes the imagecompression/decompression processor 42 to decompress compressed imagedata that has been supplied to the storage unit 55.

The compressed image data generated by the imagecompression/decompression processor 42 is supplied to a RAM 53 via thebus 50 and is stored therein. Subsequently, the data is supplied to thestorage unit 55 for recording in a memory or hard disk, a memory card 61connected to a memory I/F 59 for recording, or a communication unit 58for transfer to another apparatus.

The CPU 51 controls components or performs various pieces of processingin accordance with a program stored in a ROM 52 or a program loaded intothe RAM 53 from the storage unit 55 including a flash memory. The RAM 53also stores data that is necessary for the CPU 51 to perform variouspieces of processing. The CPU 51 is connected to an external operationinput unit 54 for receiving an operational signal input by a user.

The CPU 51, the ROM 52, and the RAM 53 are connected to one another viathe bus 52. The bus 50 is also connected to the storage unit 55including a non-volatile memory or a hard disk, a display control unit56 for controlling an image to be displayed on an LCD 19, and the memoryI/F 59 to which the memory card 61 is attached.

The display control unit 56 stores image data decompressed by the DSP 35in a VRAM included therein, and causes the LCD 19 to display an imagecorresponding to the image data stored in the VRAM or an imagecorresponding to image data stored in another memory.

The bus 50 is connected to a drive 63 via an interface as appropriate soas to install a program read from a magnetic disk 64, an optical disc65, a magneto-optical disk 66, or a memory 67 connected to the drive 63into the storage unit 55 or the like. A program read from the memorycard 61 that is attached to the memory I/F 59 as appropriate is alsoinstalled into the storage unit 55 if necessary.

The CPU 51 controls the operations of the CDS circuit 32, the AGCcircuit 33, and the A/D converter 34 on the basis of control informationinput by a user with the external operation input unit 54, controlinformation supplied from the image adjustment processor 41, orinformation obtained by executing various programs. Furthermore, the CPU51 controls the operation of the CCD 31 by controlling a TG (TimingGeneration unit) 71 for controlling the drive of the CCD 31 and a Vdriver 72. Still furthermore, the CPU 51 controls an iris shutter driver73 for controlling the operation of the lens unit 12 so as to adjust ashutter speed or a diaphragm mechanism.

For example, under the control of the CPU 51, the communication unit 58transmits or receives via a wire/wireless communication link variouspieces of information including image data of a captured image to orfrom an image pickup apparatus such as another camera with which thecamera 100 can communicate.

FIG. 2 is a block diagram illustrating a main functional configurationof a camera according to the first embodiment of the present invention.

The camera 100 according to this embodiment includes a feature valueextraction unit 102, a feature value transfer unit 104, a feature valuereception unit 106, a first determination unit 108, a feature valuestorage unit 110, an image data transfer unit 112, an image datareception unit 114, a second determination unit 116, an image datastorage unit 118, an image data storage unit 120, and an identificationinformation storage unit 122.

The feature value extraction unit 102 is a functional configuration unitfor extracting a feature value from image data. The feature valuetransfer unit 104 is a functional configuration unit for transferring toanother unspecified camera a feature value extracted from image data tobe exchanged and identification information allowing identification of acamera (the camera 100) from which the extracted feature value is to betransferred. The feature value reception unit 106 is a functionalconfiguration unit for receiving from another unspecified camera afeature value and identification information of the unspecified camerafrom which the feature value has been transferred. The firstdetermination unit 108 is a functional configuration unit fordetermining whether the received feature value matches a feature valueincluded in image data of a captured image. The feature value storageunit 110 is a functional configuration unit for storing a plurality offeature values received from other unspecified cameras and pieces ofidentification information identifying these cameras from which thefeature values have been transferred.

The image data transfer unit 112 is a functional configuration unit for,when it is determined by the first determination unit 108 that there isa match between the feature value received from another unspecifiedcamera and the feature value included in the image data of the capturedimage, transferring to the unspecified camera the image data of thecaptured image and identification information identifying theunspecified camera from which the feature value has been transferred andthen been received. The image data reception unit 114 is a functionalconfiguration unit for receiving from another unspecified camera imagedata of a captured image and identification information identifying acamera (the camera 100) from which a feature value included in the imagedata of the captured image has been transferred. The seconddetermination unit 116 is a functional configuration unit fordetermining whether the received identification information matchesidentification information of a camera (the camera 100) that hasreceived the identification information from another unspecified camera.The image data storage unit 118 is a functional configuration unit for,when it is determined by the second determination unit 116 that there isa match between the received identification information and theidentification of the camera 100, storing the received image data of thecaptured image. The image data storage unit 120 is distinguished fromthe image data storage unit 118, and is a functional configuration unitstoring image data in advance. The identification information storageunit 122 is a functional configuration unit for storing theidentification information of the camera 100.

For example, each of the feature value transfer unit 104, the featurevalue reception unit 106, the image data transfer unit 112, and theimage data reception unit 114 is composed of the communication unit 58,etc. For example, each of the first determination unit 108 and thesecond determination unit 116 is composed of the CPU 51, etc., andoutputs a control signal to another functional configuration unit. Forexample, the feature value extraction unit 102 is composed of the DSP35, the CPU 51, etc. For example, the feature value storage unit 110 iscomposed of the combination of the RAM 53, the storage unit 55, thememory I/F 59 and the memory card 61, etc. For example, each of theimage data storage units 118 and 120 is composed of the combination ofthe drive 63 and the recording media 64 to 67, etc. For example, theidentification information storage unit 122 is composed of the ROM 52,etc. The above-described configuration is an example only, and theconfiguration of the camera 100 is not limited thereto.

FIGS. 3 and 4 are schematic diagrams describing an image data exchangemethod according to this embodiment. FIGS. 5 and 6 are flowchartsillustrating an image data exchange method according to this embodiment.FIGS. 3 and 5 illustrate a feature value extraction and transferprocess. FIGS. 4 and 6 illustrate a feature value comparison and imagetransfer process.

First, the feature value extraction and transfer process will bedescribed. In the feature value extraction and transfer process, afeature value included image data of a captured image is extracted, andthe extracted feature value and identification information of a cameraare transferred to another unspecified camera for storage.

FIG. 3 illustrates a case in which the image of a photographer AP who isan operator of a camera A is captured by the camera A, and the image ofa photographer BP who is an operator of a camera B is captured by thecamera B, and the image data of the captured image of the photographerAP and the image data of the captured image of the photographer BP areexchanged between the cameras A and B. Pieces of image data may beexchanged among three or more cameras. Pieces of image data of images ofspecific subjects other than photographers may be exchanged.

In an example illustrated in FIG. 3, first, the camera A captures theimage of the photographer AP so as to specify subject image dataincluded in image data to be transferred from one camera to anothercamera (step S10). Next, a feature value AP is extracted from thecaptured image of the subject (the photographer AP) (step S12). Thefeature value AP of the subject image and identification information0001 of the camera A are transferred to unspecified cameras includingthe camera B (step S14). On the other hand, the camera B stores thefeature value AP and the identification information 0001 which have beenreceived from the camera A (step S40).

Here, the feature value of a subject image denotes parameter informationused to identify the subject image included in an image corresponding toimage data. In the following, a method of identifying a subject image onthe basis of the feature value of a subject image and the face image ofthe subject will be briefly described. A subject image used in thisembodiment is not limited to the face image of a subject, and may be animage having another feature such as color or shape of a subject. Asubject may not be a person.

In order to identify a subject image on the basis of the face image of asubject, first, an image area representing the face of a subject isdetected from an image corresponding to image data using a templatedefining an average facial feature and is then extracted as a faceimage. Subsequently, the correlation between the feature value of theextracted face image and the feature value of each of a plurality offace images registered in advance is examined, and one of the registeredface images having the highest correlation with the extracted face imageis identified as the face image of the subject. Here, for example, atthe time of extracting from a face image a feature value that iseffective for identification of the face image, signal processing suchas edge image processing, frequency intensity image processing,high-order autocorrelation processing, or color conversion imageprocessing is performed. For example, parameter information representingthe face feature of a subject, for example, parameter informationrepresenting the eyes or nose of a subject, is extracted as the featurevalue of a face image.

The identification information of a camera is the manufacture's serialnumber of the camera or information allowing identification of aspecific camera, for example, the communication address of a camerahaving a communication function. Other unspecified cameras are camerasexisting within the wire/wireless communication range of a correspondingcamera.

In the feature value extraction and transfer process, if the imagecapturing (step S10) is not performed, a feature value may be extractedfrom image data that has already been stored in the camera A and then betransferred to other unspecified cameras along with the identificationinformation of the camera A.

In the following description, as in the camera A, in the camera B, it isassumed that the image capturing of the photographer BP (step S30), theextraction of a feature value BP from image data (step S32), and theautomatic transfer of the feature value BP and identificationinformation 0002 (step S34) are performed. On the other hand, in thecamera A, it is assumed that the storage of the feature value BP and theidentification information 0002 (step S20) is performed. Theabove-described process may be performed only in the camera A. A processsimilar to that performed in the camera A may not be performed in thecamera B. If pieces of image data are exchanged among the cameras A andB and a camera C, a process similar to that performed in the cameras Aand B may be performed in the camera C.

Next, a feature value comparison and image transfer process will bedescribed. In the feature value comparison and image transfer process, afeature value included in image data of a captured image isautomatically extracted. The extracted feature value is compared with afeature value received from another unspecified camera. If these featurevalues are the same, the image data and corresponding identificationinformation are transferred to the unspecified camera. If image data andthe camera's own identification information are received from anotherunspecified camera, the image data is stored in the camera.

FIG. 4 is a diagram illustrating the same case as that illustrated inFIG. 3 in which pieces of image data of captured images of thephotographers AP and BP are exchanged between the cameras A and B.

In an example illustrated in FIG. 4, first, the camera A captures animage including a specific subject (step S52). For example, if the imageof the photographer BP is captured, the feature value BP of the subjectimage (the image of the photographer BP) included in the captured imageis automatically extracted (step S54). The extracted feature value iscompared with the feature value BP of a subject image stored in advancein the feature value extraction and transfer process (step S56). Ifthese feature values are the same, image data and the identificationinformation 0002 that is stored in the camera A along with the featurevalue BP are transferred to other unspecified cameras including thecamera B (step S58).

In the feature value comparison and image transfer process, if the imagecapturing (step S52) is not performed, the feature value of a subjectimage may be extracted from image data that has already been stored inthe camera A and then be compared with a transferred feature value. Ifthese feature values are the same, the image data may be transferred toother unspecified cameras along with identification information.

Furthermore, if the image capturing is not performed, it is determinedwhether image data has been received from another unspecified camera(step S60). If it is determined that image data has been received,identification information that has been received along with the imagedata is compared with the camera's own identification information 0001(step S62). If these pieces of identification information are the same,the received image data is stored in the camera A (step S64).

The process from the extraction of a feature value from image data (stepS54) to the transfer of image data and identification information (stepS58) and the process from the reception of image data (step S60) to thestorage of the image data (step S64) are automatically performed withouta user's operation.

As in the camera A, in the camera B, the image capturing of thephotographer AP (step S72), the automatic extraction of the featurevalue AP from image data (step S74), the automatic comparison betweenfeature values (step S76), the automatic transfer of image data andidentification information 0001 (step S78), the automatic reception ofimage data and identification information (step S80), the automaticcomparison between pieces of identification information (step S82), andthe automatic storage of image data (step S84) are performed. If piecesof image data are exchanged among the cameras A, B and C, a processsimilar to that performed in the cameras A and B may be performed in thecamera C.

Consequently, between the cameras A and B, or among the cameras A, B,and C, image data of an image including the photographer AP isautomatically stored in the camera A that wants to obtain the imagedata, and image data of an image including the photographer BP isautomatically stored in the camera B that wants to obtain the imagedata.

FIG. 5 illustrates the feature value extraction and transfer processperformed in a specific camera in detail.

In the feature value extraction and transfer process, first, it isdetermined whether image capturing is performed (step S100). If theimage capturing is performed, an image including a specific subject iscaptured (step S102). Subsequently, if a desired subject image isincluded in the captured image, the feature value of the subject imageis extracted from image data by a user's operation (step S104). If theextracted feature value of the subject image is transferred to otherunspecified cameras, the feature value of the subject image and thecamera's own identification information allowing the identification ofthe camera are transferred by a user's operation (step S106). Here, forexample, pieces of relevant information about image capturing conditionsand the user of the camera may be transferred along with the camera'sown identification information.

On the other hand, if the image capturing is not performed, it isdetermined whether a feature value and identification information havebeen received from another unspecified camera (step S108). If a featurevalue and identification information have been received, it isdetermined by a user's operation whether requested exchange processingis performed on the basis of the identification information of a cameraand relevant information (step S110) If the exchange processing isperformed, the received feature value of a subject image which isincluded in image data to be exchanged and the identificationinformation of a camera from which the feature value has beentransferred are stored (step S112). On the other hand, if the exchangeprocessing is not performed, the received pieces of information aredeleted without being stored.

If the feature value and the identification information have not beenreceived, if the requested exchange processing is not performed, or ifthe received feature value and the received identification informationare stored, the process returns to the determination of whether imagecapturing is performed (step S100) so as to continue the feature valueextraction and transfer process unless other processes including thefeature value comparison and image transfer process are requested.

FIG. 6 illustrates the feature value comparison and image transferprocess performed in a specific camera in detail.

In the feature value comparison and image transfer process, first, it isdetermined whether image capturing is performed (step S150). If theimage capturing is performed, an image including a specific subject iscaptured (step S152). Subsequently, the feature value of a subject imageis extracted from image data (step S154). The extracted feature value iscompared with a feature value of a subject image included in image datato be exchanged which has been received from another unspecified cameraand then been stored (step S156). If these feature values are the same,image data and identification information that has been stored alongwith the feature value are transferred to other unspecified cameras(step S158). On the other hand, if these feature values are not thesame, the image data is stored without being transferred in the samemanner as in the case of normal image capturing. If these feature valuesare not the same, or if the image data and the identificationinformation have been transferred, the process returns to thedetermination of whether image capturing is performed (step S150) so asto continue the feature value comparison and image transfer process.

On the other hand, if it is determined (in step S150) that imagecapturing is not performed, it is determined whether image data andidentification information have been received from another unspecifiedcamera (step S160). If image data and identification information havebeen received, the received identification information is compared withthe camera's own identification information (step S162). If these piecesof identification information are the same, the received image data isstored (step S164). On the other hand, if these pieces of identificationinformation are not the same, the received image data is deleted withoutbeing stored. If image data has not been received, or if these pieces ofidentification information are not the same, the process returns to thedetermination of whether image capturing is performed (step S150) so asto continue the feature value comparison and image transfer process.

In the examples illustrated in FIGS. 3 and 4, the camera A specifies thefeature value AP of the image of the photographer AP, and the camera Bspecifies the feature value BP of the image of the photographer BP.Thus, each camera specifies a single feature value. However, each cameramay specify a plurality of feature values.

FIG. 7 is a schematic diagram illustrating a feature value extractionand transfer process performed when a plurality of feature values arespecified. The feature value extraction and transfer process illustratedin FIG. 7 is performed subsequent to the feature value extraction andtransfer process illustrated in FIG. 3.

In an example illustrated in FIG. 7, after transferring the featurevalue AP of the image of the photographer AP, the camera A captures theimage of a subject CP so as to specify an additional subject image (stepS10). Subsequently, a feature value CP of the subject image is extractedfrom the image data of the subject CP (step S12). The feature value CPof the subject image is transferred to other unspecified camerasincluding the camera B along with the identification information 0001 ofthe camera A and an addition flag (step S16). The camera B stores thefeature value CP and the identification information 0001 which have beenreceived from the camera A (step S40). In the camera B, a processsimilar to that performed in the camera A may be performed.

Since the feature value CP and the addition flag are transferred, thecamera B stores the feature value CP in addition to the feature value APof the image of the photographer AP that has already been stored. As aresult, pieces of image data corresponding to a plurality of subjectimages (the images of the photographers AP and BP) can be automaticallyexchanged between the cameras A and B in accordance with the featurevalues and the identification information which have been received.Instead of adding the feature value of a different subject, the featurevalue of the same subject may be added. As a result, for example, imagedata to be exchanged can be exchanged in accordance with the featurevalues of subject images that have been captured from various angles.

If the feature value AP of the subject image which has already beentransferred to other unspecified cameras is updated, an update flag maybe used instead of the addition flag. The update flag is transferredalong with information (for example, AP) specifying the feature valuethat has not been updated yet. For example, if the feature value AP ofthe image of the photographer AP is updated, the image of thephotographer AP is recaptured so as to extract a feature value AP′ fromimage data. The feature value AP′ is transferred to other unspecifiedcameras including the camera B along with the identification informationof the camera A and the update flag.

Accordingly, since the feature value AP′ is transferred along with theupdate flag, the camera B exchanges image data on the basis of theupdated feature value AP′ instead of the feature value AP of the imageof the photographer AP which has already been stored. Accordingly, byupdating a feature value, the accuracy of comparing the feature valuesof subject images can be improved.

As described previously, according to an image data exchange methodaccording to this embodiment, on the basis of the feature value of asubject image included in image data to be exchanged, correspondingimage data is automatically transferred to/from another unspecifiedcamera. Accordingly, a plurality of cameras can efficiently exchangepieces of image data to be exchanged with each other. Furthermore,corresponding image data is automatically transferred to/from anotherunspecified camera along with the identification of a camera that wantsto obtain the image data. Accordingly, a plurality of cameras canefficiently exchange pieces of image data to be exchanged with eachother in accordance with the determination result of the identificationinformation. At the time of exchanging pieces of image data, there areno operational burdens on users, for example, the determination of imagedata, an operation for establishing a connection, and the deletion ofimage data. Furthermore, the electric power for the operation of acamera can be prevented from being wasted due to an inefficient user'soperation such as an operation for establishing a connection for eachpiece of image data or the transfer or deletion of unnecessary imagedata. Consequently, even in a case in which it is necessary to obtainimage data of a captured image of a specific subject, a plurality ofcameras can efficiently exchange pieces of image data with each other.

Second Embodiment

An image data exchange method according to the second embodiment of thepresent invention will be described while avoiding repetition of thedescription that has already been made in an image data exchange methodaccording to the first embodiment.

FIG. 8 is a block diagram illustrating a main functional configurationof a camera according to the second embodiment of the present invention.A camera 150 according to this embodiment includes a feature valueextraction unit 152, a feature value transfer unit 154, a feature valuereception unit 156, a first determination unit 158, a feature valuestorage unit 160, an image data transfer unit 162, an image datareception unit 164, and image data storage units 168 and 170.

The feature value transfer unit 154 is a functional configuration unitfor transferring to another unspecified camera a feature value extractedfrom image data to be exchanged. The feature value reception unit 156 isa functional configuration unit for receiving from another unspecifiedcamera a feature value. The first determination unit 158 is a functionalconfiguration unit for determining whether the received feature valuematches a feature value included in image data of a captured image. Theimage data transfer unit 162 is a functional configuration unit fortransferring image data to another unspecified camera when the featurevalues are the same. The feature value storage unit 160 is a functionalconfiguration unit for storing a plurality of feature values receivedfrom other unspecified cameras.

The image data reception unit 164 is a functional configuration unit forreceiving image data of a captured image transferred from anotherunspecified camera. The image data storage unit 168 is a functionalconfiguration unit for storing the received image data of the capturedimage.

FIG. 9 is a schematic diagram describing a feature value extraction andtransfer process performed in an image data exchange method according tothis embodiment.

In a feature value extraction and transfer process according to thisembodiment, a feature value is extracted from image data of a capturedimage, and the extracted feature value is transferred to anotherunspecified camera for storage. Accordingly, unlike a feature valueextraction and transfer process according to the first embodiment, theidentification information of a camera from which the feature value isto be transferred is not transferred. For example, instead oftransferring no identification information of a camera, identificationinformation with which no specific camera can be identified, forexample, a number assigned to no cameras, may be transferred.

In an example illustrated in FIG. 9, first, the camera A captures theimage of the photographer AP so as to specify a subject image includedin image data to be exchanged (step S10). Next, the feature value AP ofthe subject image (the image of the photographer AP) is extracted fromthe image data of the captured image of the photographer AP (step S12).The feature value AP of the subject image is transferred to otherunspecified cameras including the camera B (step S18). On the otherhand, the camera B stores the feature value AP that has been receivedfrom the camera A (step S42). Accordingly, the identificationinformation 0001 of the camera A is not transferred to other unspecifiedcameras including the camera B, and is not stored in the unspecifiedcameras including the camera B.

In the following description, as in the camera A, in the camera B, it isassumed that the image capturing of the photographer BP (step S30), theautomatic extraction of the feature value BP from image data (step S32),and the automatic transfer of the feature value BP (step S38) areperformed. On the other hand, in the camera A, it is assumed that thestorage of the feature value BP (step S22) is performed. Theabove-described process may be performed only in the camera A. A processsimilar to that performed in the camera A may not be performed in thecamera B. If pieces of image data are exchanged among the cameras A, Band C, a process similar to that performed in the cameras A and B may beperformed in the camera C.

Next, a feature value comparison and image transfer process according tothis embodiment will be described. As in a feature value comparison andimage transfer process according to the first embodiment, in a featurevalue comparison and image transfer process according to thisembodiment, the image capturing of a subject, the automatic extractionof a feature value from image data, the automatic comparison betweenfeature values, the automatic transfer of image data and identificationinformation, the automatic reception of image data and identificationinformation, the automatic comparison between pieces of identificationinformation, and the automatic storage of image data are performed.

In a feature value extraction and transfer process according to thisembodiment, however, at the time of transferring the feature value of asubject image included in image data to be exchanged, the identificationinformation of a camera from which the feature value is to betransferred is not transferred along with the feature value.Accordingly, an extracted feature value is compared with a feature valuethat has been received from another unspecified camera. If these featurevalues are the same, only image data is transferred to other unspecifiedcameras without the identification information of the unspecified camerafrom which the feature value has been transferred. If image data isreceived from another unspecified camera, identification information isnot received along with the image data. Since the comparison betweenpieces of identification information is not performed (or it isdifficult to identify a camera from which the image data has beentransferred), the image data received from the unspecified camera isstored regardless of a camera from which the image data has beentransferred.

Consequently, between the cameras A and B, or among the cameras A, B,and C, image data of an image including the photographer AP isautomatically stored in the camera A that wants to obtain the image dataor in the cameras A and C, and image data of an image including thephotographer BP is automatically stored in the camera B that wants toobtain the image data or in the cameras B and C.

As in an image data exchange method according to the first embodiment,in an image data exchange method according to this embodiment, eachcamera may specify a plurality of feature values. As a result, among aplurality of cameras, pieces of image data to be exchanged correspondingto a plurality of images each including a subject image can beautomatically exchanged.

As described previously, according to an image data exchange methodaccording to this embodiment, on the basis of the feature value of asubject image included in image data to be exchanged, correspondingimage data is automatically transferred to/from other unspecifiedcameras. Accordingly, a plurality of cameras can efficiently exchangepieces of image data to be exchanged with each other. Consequently, evenin a case in which it is necessary to obtain image data of a capturedimage of a specific subject, a plurality of cameras can efficientlyexchange pieces of image data with each other.

Although the preferred embodiments of the present invention have beendescribed above with reference to the accompanying drawings, the presentinvention is not limited thereto. It is obvious that various changes andmodifications of the embodiments can be made by those skilled in the artwithout departing from the spirit and scope of the present invention.Accordingly, it should be understood that these changes andmodifications fall within the scope of the present invention.

For example, a camera is used above to describe an image processingapparatus and an image processing method according to an embodiment ofthe present invention. However, the present invention can be applied to,for example, a video camera or various types of mobile terminals capableof capturing a still image. Furthermore, pieces of image data may beexchanged between different types of apparatuses, for example, between acamera and a video camera or among a camera and various types of mobileterminals.

1. An image processing apparatus for achieving the exchange of pieces ofimage data between a plurality of image processing apparatuses,comprising: a feature value extraction unit configured to extract afeature value included in image data; a feature value transfer unitconfigured to transfer to another image processing apparatus a featurevalue extracted from image data to be exchanged; a feature valuereception unit configured to receive a feature value transferred fromthe other image processing apparatus; a first determination unitconfigured to determine whether the received feature value matches afeature value included in image data of a captured image; an image datatransfer unit configured to transfer the image data of the capturedimage to the other image processing apparatus when there is a matchbetween the feature values; and an image data reception unit configuredto receive image data of a captured image transferred from the otherimage processing apparatus.
 2. The image processing apparatus accordingto claim 1, further comprising a second determination unit, and whereinthe feature value transfer unit transfers identification informationallowing identification of the image processing apparatus from which thefeature value extracted from image data to be exchanged is to betransferred along with the extracted feature value, wherein the featurevalue reception unit receives identification information of the otherimage processing apparatus from which the feature value has beentransferred along with the transferred feature value, wherein, when thefirst determination unit determines that there is a match between thefeature values, the image data transfer unit transfers to the otherimage processing apparatus the identification information of the otherimage processing apparatus from which the feature value has beentransferred and then been received along with the image data of thecaptured image, wherein the image data reception unit receives from theother image processing apparatus the identification of the imageprocessing apparatus from which the feature value included in the imagedata of the captured image has been transferred along with the imagedata of the captured image, and, wherein the second determination unitdetermines whether the identification information received from theother image processing apparatus matches identification information ofthe image processing apparatus that has received the identificationinformation from the other image processing apparatus.
 3. The imageprocessing apparatus according to claim 1, further comprising an imagedata storage unit configured to store the received image data of thecaptured image.
 4. The image processing apparatus according to claim 2,further comprising an image data storage unit configured to store thereceived image data of the captured image when the second determinationunit determines that there is a match between the pieces ofidentification information.
 5. The image processing apparatus accordingto claim 1, further comprising a feature value storage unit configuredto store a plurality of feature values received from the other imageprocessing apparatus, and wherein the first determination unitdetermines whether the feature value included in the image data of thecaptured image matches the plurality of stored feature values, andwherein the image data transfer unit transfers to the other imageprocessing apparatus the image data of the captured image when there isa match among the feature values.
 6. The image processing apparatusaccording to claim 2, further comprising a feature value storage unitconfigured to store a plurality of feature values received from theother image processing apparatus and identification information of theother image processing apparatus from which the plurality of featurevalues have been transferred, and wherein the first determination unitdetermines whether the feature value included in the image data of thecaptured image matches the plurality of stored feature values, andwherein, when there is a match among the feature values, the image datatransfer unit transfers to the other image processing apparatus theidentification information of the other image processing apparatus fromwhich the plurality of feature values have been transferred along withthe image data of the captured image.
 7. The image processing apparatusaccording to claim 1, wherein the feature value extraction unit extractsa feature value of a subject face image included in image data, andwherein the first determination unit determines whether the extractedfeature value of the subject face image matches a feature value of asubject face image received from the other image processing apparatus.8. An image processing method of achieving the exchange of pieces ofimage data between a plurality of image processing apparatuses,comprising the steps of: receiving a feature value included image datato be exchanged from another image processing apparatus; extracting afeature value included in image data of a captured image; determiningwhether the extracted feature value matches the received feature value;and transferring the image data of the captured image to the other imageprocessing apparatus when there is a match between the feature values.9. The image processing method according to claim 8, wherein, in thereceiving step, identification information allowing identification ofthe other image processing apparatus from which the feature valueincluded in image data to be exchanged has been transferred is receivedalong with the feature value, and wherein, in the transferring step,when it is determined in the determining step that there is a matchbetween the feature values, the identification information of the otherimage processing apparatus from which the feature value has beentransferred and then been received is transferred to the other imageprocessing apparatus along with the image data of the captured image.